Every so often, I will have a discussion with someone who wants to share their new “big idea” with me. Some of them make sense. Others, less so. For example, it was recently proposed to me that everyone has a soul, and it is the pattern of electricity in your brain. This pattern lives on after you die. The rather scary thing is that this idea was suggested to me by a neuroscientist getting her Ph.D. Aside from wondering “what does that even mean?”, one cannot help but notice the belief as attire in the idea.
And invariably, after objecting to these strange ideas, I will be told, "Don't be so closed-minded! There is so much that we don't know!"
Now, this is a strange form of belief as attire. It is the belief of the sophisticated person, who knows that since everything is a shade of gray, all is equal. It is very much rooted in dark side epistemology. In acknowledging their ignorance, they glory in the fundamental unknowability of the universe. "After all, if we don't know the truth, all explanations are equal! Who's to say that I am wrong? You can't disprove my theory!"
In general, I like to think of myself as open-minded. I support gay marriage, I am pro-choice, etc. And yet, doesn't everyone think they are open-minded? Do I discard legitimately promising ideas? Do I make too many false negative errors? I thought about it for some time and came to the conclusion: No, that idea was just plain silly.
Sometimes, when faced with a new idea, the instinct is to discard it out of hand. Sometimes we try not to believe new ideas, especially if they contradict long-held and deeply-rooted beliefs. And occasionally, the idea is correct, and you really do need to do a mental overhaul. However, that is often not the case.
A few million results come up in a google search for "benefits of homeopathy". However, I do not entertain homeopathy as a legitimate means of curing ailments. I have been told repeatedly of the existence of God. However, after the point where I understood the notion of "beliefs as anticipation-controllers", I held a strictly naturalistic worldview. I am dismissive of theories that do not fit this worldview.
I am skeptical to the extreme of implausible ideas. That is, after all, what closed-mindedness is. The measure of open-mindedness is merely about which ideas seem implausible to me. I tend to believe that if scientific education was better and more widespread, then people would become more skeptical of ideas that don't make sense. Of course, there is always the difficulty that one might end up being skeptical of strange but true ideas, such as cryonics.
So then the real benefit of closed-mindedness is this: it saves you the time of having to entertain silly notions. But remember the danger in too much of a good thing! Some wacky ideas are true. A simple test is to list as many problems with the idea as you can think of in one minute. If you've listed three or more seemingly intractable problems, and the one explaining it to you cannot solve them, then being closed-minded is probably a good idea. If, however, you can only think up a couple of problems, or the one can dispel your doubts, then it may be time to look into the idea further.